meta-wistron: Initial commit for meta-lannister

Add initial commit for Lannister platform.
Lannister is an x86 server platform with an ast2600 BMC.
Update OWNER list.

Tested:
1.Build Lannister image successfully.
2.The image can boot on Lannister platform.

Signed-off-by: Bob King <Bob_King@wistron.com>
Change-Id: Ibf2b8a30b56722f2fd555d356d76d199e7a9dae5